All Climate Events

Thursday, November 9, 2017. 12:00PM. Webinar: Tracking progressive oxygen loss in ancient oceans. Chadlin M. Ostrander, Arizona State University. Sponsored by NOAA Star Center for Satellite Applications and Research. More information here.

Right now, Earth’s oceans are losing oxygen. Increasing surface temperature is decreasing the solubility and ventilation of oxygen throughout the ocean, and nutrients within wastewaters are enhancing the consumption of oxygen in more localized pockets (e.g. seasonally in the Gulf of Mexico). This is bad news for marine habitats, and also for the humans who rely on them. This is not the first time Earth’s oceans have experienced large-scale oxygen loss, however, as many previous episodes have been identified in the geologic record. In this presentation, I will discuss some new and existing geochemical evidence for a progressive loss of oxygen in Earth’s oceans preserved in ancient marine sedimentary rocks leading to a major climatic event known as Oceanic Anoxic Event 2. The processes driving large-scale marine deoxygenation 94 million years ago are very similar to what is occurring today, and thus allow for an unfortunate but timely comparison.